Growth hormone and prolactin secretion of pituitary adenoma.

Tissue culture of 20 pituitary adenomas (four acromegalies, 15 non-functioning tumors, one Forbes-Albright syndrome) was performed with the Maxmow double cover glass assembly. Growth hormone and prolactin in the medium were measured during the culture. Morphological feature in vitro was also compared with that of the original tumor. In chromophobe adenomas of clinically non-functioning, tumor cells had round secretory granules of not only 100, but also 300 mμ in diameter. The study of their tissue culture revealed that these tumor cells were secreting growth hormone in all the cases. In acromegalic patients, the culture medium a month later still contained more than 1000 ng/ml of growth hormone and also many secretory granules remained in the cultured cells. Thus, it was suspected that the tumor cells in acromegalic patients had autonomous secretory functions of growth hormone. In pituitary adenomas of Forbes-Albright syndrome and even non-functioning or acromegaly, prolactin secretion from tumor cells was demonstrated. Ovoid, ellipsoid, or irregular secretory granules of 500 to 1000 mμ in acromegalic patients and 150 to 500 mμ in the other cases were observed with an electron microscope. Key word: pituitary adenoma, acromegaly, Forbes-Albright syndrome, growth hormone, prolactin, tissue culture.